Here au nique single-crystal-to-single-crystal (SCSC) transformationo fa116-nuclear Au I 72 Cd II 40 Na I 4 cageof-cage( 2 CdNa )i sreported, which was created from at rigold(I) metalloligand with d-penicillamine by way of a9 -nuclear Au I 6 Cd II 3 cage (1). Cage-of-cage 2 CdNa is composedo f1 2 cages of 1 that are linked by 4C d 2 + and 4N a + ions, with its surface being covered by 12 NO 3 À ions to form ad iscrete, spherical molecule with ad iameter ca. 4.7 nm. In crystal 2 CdNa ,t he cage-of-cage molecules are packed in ac ubic lattice with ah uge cell volumeo fc a. 4.5 10 5 3 , so as to have large interstices with diameters of more than 3nm. Upon soakingc rystals 2 CdNa in aqueous Cu(NO 3 ) 2 ,a ll Cd 2 + and Na + were quicklye xchanged by Cu 2 + to producea na nalogous Au I 72 Cu II 44 cage-of-cage (2 Cu )i naSCSC manner.P rolonged soakingl ed to the SCSC transformation to anothers upramolecular structure (2' Cu )c onsisting of 152-nuclear Au I 72 Cu II 80 cage-of-cages that are alternately H-bonded with the Au I 72 Cu II 44 cage-of-cages. 2' Cu showed the accommodationo f MoO 4 2À and the conversion of MoO 4 2À to b-Mo 8 O 26 4À in the crystal, with retention of single-crystallinity. Supporting information and the ORCID identification number(s) for the author(s) of this articlecan be found under: https://doi.org/10.1002/chem.201904275.Scheme1.Synthetic routes to 1 and 2 CdNa .C olor codes: red,A u; cream, Cd; purple, Na.

Soaking crystals of an AuI72CdII40NaI4 cage-of-cage in aqueous Co(NO3)2 afforded an analogous AuI72CoII44 cage-of-cage, accompanied by the exchange of NaI and CdII by CoII with retention of the single crystallinity....